This invention relates to a method to feed multiple catalysts systems into a polymerization reactor, preferably a gas or slurry phase polymerization reactor.
The demands of polyolefin fabricators are increasingly becoming more and more specific. In an attempt to meet these demands polyolefin producers are attempting to create more and more specialized polyolefins that have particular product configurations. One means to do this comprises using two catalysts in the same reactor to produce intimately mixed polymer blends. The difficulty however lies in selecting compatible catalysts that will actually work together well and reactor conditions that do not benefit one catalyst while hindering another.
Mobil, in PCT patent application WO 99/03899, discloses using a metallocene type catalyst and a Ziegler-Natta type catalyst in the same reactor to produce a bimodal molecular weight distribution (MWD) high-density polyethylene (HDPE). These two catalyst however were fed into the reactor as supported powders.
U.S. Ser. No. 09/312,878 filed May 17, 1999 discloses a gas or slurry phase polymerization process using a supported bisamide catalyst.
This invention relates to a method to feed multiple catalysts systems into a polymerization reactor, preferably a gas or slurry phase polymerization reactor. The catalysts, activators and/or catalyst systems are preferably introduced into the reactor in a liquid carrier, preferably in solution. The catalysts, activators, catalysts systems, etc may be combined in different orders and in different amounts. The individual catalysts or activators may be introduced into the reactor directly or they may be combined with one or more other catalysts and or activators prior to being placed in the reactor. Further the catalysts, activators and/or catalyst systems (and the carriers) may be contacted sequentially, in series or in parallel. Each catalyst, however, is independently activated.